The present invention relates to the field of safely using high power lasers, particularly laser marking systems, and more particularly to marking systems for use in free space environments to safely mark items being processed at the marking system. The present invention also relates to medical uses of high power lasers.
Retail goods are universally labeled with product codes, such as bar codes, which are scanned at a point of sale register to determine a price of the item, as well for inventory control purposes. Typically, items are brought to a point of sale register where a clerk scans the items; however, there are also “self serve” point of sale kiosks which allow the purchaser to scan the items, as well. In the process of scanning items, it is not uncommon to forget to scan an item, or lose track of whether a given item was scanned. To determine if an item has been scanned the clerk will have to read back all the items scanned so far during the check out process and look for the item or count the number of items scanned, which takes time and slows down the check out process. The situation could be worse at self-serve check out kiosks as the purchaser may be concerned that they are being double charged for an item, while at the same time wanting to make sure they are paying for the item.
Another issue with retail sales is loss prevention. Many stores have employees stationed near the store exit to check receipts of purchases to make sure all items have been paid for. However, a receipt is only an indication that an item was paid for, but it does not necessarily ensure that the particular item in possession of the person with the receipt has been paid for as it is possible to pay for one item, return to the store, pick up another identical item, and walk out with it. The person stealing the item can present the same receipt, and the employee checking the receipt has no way of knowing if the item has actually been paid for. Some retailers have employees manually mark the receipt, but this is a less than optimal solution as people can sometimes leave without having their receipt marked during busy periods. Similarly, it is not uncommon for thieves to steal a second, identical item, and attempt to return the stolen item using the original receipt as “proof” of purchase.
The marking procedure where an employee marks the receipt is reasonably effective at stopping some “walk out” theft where a person attempts to walk out with an item identical to one already purchased, but it is far less effective at preventing return losses where a person successfully steals a second item and returns it using the original receipt. Similar issues exist in other environments, such as manufacturing and shipping. Items are moved through specific points and may be scanned
Laser marking is commonly used to mark items in controlled environments, such as in manufacturing. Safety concerns in a controlled environment are very different from those of a free space environment, such as a retail environment. Traditionally, a free space environment has restricted laser based applications to those having a minimal exposure risk. For example, the low powered lasers used to scan barcodes during retail transactions not pose a significant risk of injury to humans. Laser marking is by nature using higher powered lasers (designed to burn a physical object to mark it), which poses a significant risk of injury to humans. While some safety procedures exist for high powered laser systems operating in free space in a communication domain, no known laser marking system that incorporates appropriate safety mechanisms to operate in a free space environment exists. A marking system that can be used in a free space environment, such as for marking products at a retail point of sales system, would be beneficial.